Some examples of large artifacts that can require painting or other material coating include aircraft wings, aircraft fuselages, aircraft engine blades, wind-turbine blades, wind-tower shafts, artifacts concerning space and defense industries such rocket and missile bodies, commercial and transportation truck bodies, rail vehicles and boats.
The surfaces of such artifacts that require coating can include surfaces that have complex features including but not limited to 3-dimensional surface shapes, uneven adjacent surfaces, tapered or wedge shapes and other shapes. Such large and complex surfaces can require coating or painting with several layers of material. Further, successive coats can be of the same or different materials, and can have varying thicknesses.
Due to the characteristics of some coatings, proper application of certain coats should be performed when the underlying coating is still sufficiently wet. For example, this is required when bonding between layers occurs only when the underlying coat is sufficiently wet upon application of the subsequent overlying coat. Unless such application is made while the underlying surface is sufficiently wet, the quality of the overall coating is diminished.